This invention relates to surge voltage arresters in general and more particularly to a surge voltage arrester with an improved voltage distribution.
U.S. Pat. No. 4,369,480 describes a surge voltage arrester which comprises a column which is arranged in a housing and is formed by a multiplicity of arrester elements, several shielding bodies which enclose the column and are connected to each other by support bodies, and a device for fastening arrester elements. In the disclosed arrester, the shielding bodies are the supporting parts of the arrester elements and also have an effect on the voltage distribution over the length of the entire column of arrester elements. However, an uneven voltage distribution can nevertheless be brought about by closely adjacent grounded parts, for instance, the grounded metal encapsulation which acts as the housing of the column of arrester elements. This interferes with the operation of the surge voltage arrester.
By some surge voltage arresters, equalization of the voltage distribution has been accomplished by shunting voltage controlling elements in the form of capacitors across the series circuit of arrester elements (German Pat. No. 1 120 567). Further, in surge voltage arresters, having a column formed by arrester elements enclosed by shielding bodies, capacitors have been arranged between the shielding bodies for controlling the voltage (DE-OS No. 2 348 134, corresponding to Swiss Pat. No. 555 610).
It is an object of the invention, in an arrester such as that of U.S. Pat. No. 4,369,480 to improve the voltage distribution over the length of the surge voltage arrester, using voltage controlling elements.